The technology relates to a display panel and a display unit.
In the technical field of display units that display an image, recently, a display unit utilizing, as a light-emitting device of a pixel, a current-driven optical device such as an organic electroluminescence (EL) device has been developed, and increasingly commercialized. The current-driven optical device has emission luminance which varies depending on a value of a flowing current. The organic EL device is a self-light-emitting device unlike a device such as a liquid crystal device. The display unit utilizing the organic EL device (organic EL display unit) therefore does not need a light source (backlight), thus enabling the organic EL display unit to be more lightweight and thinner, and to have higher luminance than a liquid crystal display unit that needs a light source. Further, the organic EL device has a very high response speed of about several micro seconds, thus preventing the occurrence of an afterimage during display of a motion picture. Hence, the organic EL display unit is expected to be a mainstream next-generation flat panel display.
An active-matrix organic EL display unit has a configuration in which each scanning line is sequentially scanned for one horizontal period (1 H), and a signal voltage corresponding to an image signal is sampled and is written into a holding capacitor. That is, the line sequential scanning in a 1 H cycle allows for the writing operation of the signal voltage. When a threshold voltage and mobility of a driving transistor differ for each pixel, the organic EL device may undesirably have irregular emission luminance in the organic EL display unit, resulting in impaired uniformity of a screen. Thus, the active-matrix organic EL display unit performs a correction operation that reduces the irregular emission luminance caused by the irregular threshold voltage and the irregular mobility of the driving transistor, in addition to the linear sequential scanning in the 1 H cycle. For example, reference is made to Japanese Unexamined Patent Application Publication No. 2009-145531.